Step 1: Understanding the definition of a line
A line is a geometric figure that extends in both directions infinitely and has no endpoints.
It is typically defined as the path traced by a moving point in a single direction.
Step 2: What is the minimum number of points to define a line?
A line can be defined using any two points.
Once we have two points, a straight line can be drawn connecting them.
Step 3: Evaluating the options
(A) Distance between three dots $\Rightarrow$ A curve can pass through three points; not necessarily a line.
(B) Distance between two dots $\Rightarrow$ This defines a line segment, not an infinite line.
(C) Straight line $\Rightarrow$ This is the correct conceptual and geometric definition.
(D) None of these $\Rightarrow$ Incorrect, as (C) is correct.
\[
\boxed{\text{Correct Answer: (C) Straight line}}
\]
Self-study helps students to build confidence in learning. It boosts the self-esteem of the learners. Recent surveys suggested that close to 50% learners were self-taught using internet resources and upskilled themselves.

A student may spend 1 hour to 6 hours in a day in upskilling self. The probability distribution of the number of hours spent by a student is given below: \[ P(X = x) = \begin{cases} kx^2, & \text{for } x = 1, 2, 3, \\ 2kx, & \text{for } x = 4, 5, 6, \\ 0, & \text{otherwise.} \end{cases} \] where \( x \) denotes the number of hours. Based on the above information, answer the following questions:
1. Express the probability distribution given above in the form of a probability distribution table.
2. Find the value of \( k \).
3. (a) Find the mean number of hours spent by the student. (b) Find \( P(1 < X < 6) \).
$PQ$ is a chord of length $4\ \text{cm}$ of a circle of radius $2.5\ \text{cm}$. The tangents at $P$ and $Q$ intersect at a point $T$. Find the length of $TP$.